It is known, in the technical sector relating to terminal blocks for switchboards, that there exists the need to connect together two terminals situated alongside each other on the switchboard, in order to perform the required electrical connection. Also known are jumpers which are made of conductive material and which are designed for this purpose; among the known jumpers the following in particular may be distinguished:                jumpers which are configured with two elastic jaws designed to form the element for engagement in a seat of the terminal block with corresponding electrical contact in the transverse direction provided by the elastic force, which pushes the contact plates against the walls of a hole in a conducting bar for connecting together the opposite terminals of the terminal block (EP 1 876 674 discloses multiple connection jumpers of the jaws type having an over-moulded insulating body); and        screw-type jumpers by means of which electrical contact occurs in the vertical direction as a result of the foot of the jumper making contact on a conducting bar connecting together the opposite terminals of the terminal block, the contact being achieved by tightening a screw inside the female thread of a hole formed in said bar.        
These screw-type jumpers, although performing their function, nevertheless have a number of drawbacks arising in particular from the difficulty of separating a pair of jumpers from a strip of a plurality of said jumpers, while limiting the number of jumpers which are left singly attached to the strip and are no longer usable.
In addition the known jumpers have the drawback due to the fact that the locking screw is not electrically insulated from the outside and also tends to come loose owing to the vibrations which are generated during the movements of the terminal or owing to positioning in unsuitable environments.
U.S. Pat. No. 1,952,554 includes a plural unit terminal block integrally formed simulating a plurality of single unit blocks integrally connected together by easily frangible means of relatively small cross-section between adjacent blocks and substantially sharp V-like impressions in the frangible means extending transversely thereof for promoting the certainty of start of a frangible means fracture at a definite place.
WO 2004/105 188 A1 discloses an insulating terminal cover, which has through holes and snapping means for coupling to an insulating housing of a single unit terminal.